Marietta Chappell, Rita Shephard, Charles Gibson, and Robert Mitchem appeal their convictions of conspiracy to make, utter, and possess counterfeit securities in violation of 18 U.S.C. §§ 371, 513(a), and two substantive violations of § 513(a). Mitchem and She-phard also appeal the sentences imposed. Finding no error, we affirm.

Background

On February 14, 1992 Shephard, accompanied by Chappell, entered a Wal-Mart store in Ridgeland, Mississippi, seeking to cash what purported to be a Mississippi Power and Light (MP & L) payroll check drawn on Trustmark National Bank and payable to Serena Keaeh. Shephard presented a counterfeit MP & L identification card in support of the transaction. A cashier permitted She-phard to tender the check for a small purchase, returning over $200 in change.

The following day Shephard presented the identification card and a nearly identical faked MP & L check at a Jackson grocery store. A clerk took both documents into a back office to ask co-workers about the cheek’s genuineness. When the clerk returned Shephard was gone. Around the same time, Trustmark returned unpaid two other MP & L checks payable to Reach and cashed at Jackson grocery stores because they . bore inaccurate routing and transit numbers'.

. Shephard presented another MP & L check and identification card, both bearing Reach’s name, on February 15, 1992 at the Sunflower grocery store in Yazoo City. Manager Randy Jett refused to cash the check when Shephard could not produce a driver’s..license. Jett saw Shephard drive away in a gray car with another woman and two men. He telephoned a warning to Revin Helton, manager of the nearby Super Valu grocery store, that the four were headed his way. Minutes later Shephard entered the Super Yalu with Gibson, again presenting the MP & L check and identification card. Both fled when Helton confronted them. She-phard and Gibson entered a gray car with two other people and drove away; Helton followed in his vehicle and used his cellular telephone to alert authorities. The fleeing car, driven by Mitchem, crashed into a tree.

Yazoo City police officer Larry Davis saw Mitchem fleeing the accident scene on foot, running into nearby woods. On the wrecked ear’s back seat police found a typewriter. In the typewriter case they found three counterfeit cheeks payable to Reach drawn on Trust-mark and a counterfeit check payable to Rendre Batliner drawn on First American Bank. Examination of the typewriter ribbon indicated that it had produced the counterfeit checks and identity documents used by the four. A search of the car further yielded a lamination kit, 15 blank documents, ^[1] a South Carolina identification card bearing Mit-chem’s name and photograph, and a booklet handwritten by Mitchem entitled “Target 92,” detailing plans for a large scale check-passing scheme. Authorities broadcast a description of Mitchem and arrested Gibson, Chappell, and Shephard. A search for Mit-chem in the immediate area proved fruitless.

Approximately two hours later Yazoo City deputy sheriff Randy Veazey, who had participated in the initial search for Mitchem, saw a man attempting to flag a car a short distance from the crash site. As the man’s[*1098] physical appearance and clothing met the broadcast description of Mitchem and he appeared to have been running through the woods and responded evasively to an offer of assistance, Veazey requested identification. When the man produced no identification, Veazey took him into custody. While in custody, after police identified him and provided Miranda warnings, Mitchem consented in writing to a search of his Jackson hotel room. The search revealed Shephard’s Kentucky identification and 36 blank documents identical to those found in the getaway ear, all bearing Mitchem’s fingerprints. They also found a billfold containing Chappell’s identification and a letter addressed to Kendre Bat-liner, produced by the typewriter found in the vehicle.

The grand jury returned a four-count indictment ¿gainst Chappell, Mitchem, Gibson, and Shephard. Count One charged conspiracy to make, utter, and possess counterfeit securities with intent to deceive in violation of 18 U.S.C. §§ 371, 513(a). Counts Two and Three charged violations of 18 U.S.C. §§ 2, 513(a) arising from presentation of counterfeit checks at the Sunflower and Super Valu markets, respectively. ^[2] The district court denied pretrial motions by all defendants to dismiss the indictment and by Mitchem to suppress evidence recovered as a result of his arrest, including that from his hotel room. After the government’s case-in-chief and again at the close of evidence all defendants unsuccessfully moved for judgment of acquittal. The jury found the defendants guilty on all three counts, and the trial court denied post-trial motions. The district court imposed concurrent 21-month prison terms on Chappell, Gibson, and Shephard, and concurrent S-L-month prison terms on Mitchem. It further sentenced each to concurrent three-year supervised release terms, restitution, and the statutory assessments. All four defendants timely appealed.

Analysis

1. Sufficiency of the Evidence

The defendants each challenge the sufficiency of the evidence. Mindful that weight and credibility assessments lie within the exclusive province of the jury, ^[3] in considering this claim we view the evidence and draw all reasonable inferences most favorable to the verdict. ^[4] If the evidence so viewed would permit a rational jury to find all elements of an offense proven beyond a reasonable doubt, we must affirm the conviction. ^[5] The evidence need not exclude all hypotheses of innocence. ^[6]

In a prosecution under 18 U.S.C. § 513(a), ^[7] the government must prove that the defendants: (1) made, uttered, or possessed (2) a counterfeit security (3) of an organization (4) with intent to deceive another person, organization, or government. To obtain a conspiracy conviction under 18 U.S.C. § 371, the government had to demonstrate an agreement by two or more persons to violate the law, an overt act by any coconspirator in furtherance of the scheme, and each defendant’s knowing and voluntary participation. ^[8] Concert of action may give rise to an inference that defendants entered into the requisite agreement. ^[9]

[*1099] Defendants claim that because the government failed to demonstrate any connection of the Super Valu and Sunflower supermarkets to interstate commerce, the district court should have granted their motions for judgment of acquittal. We find this argument unpersuasive. While section 513(c)(4) defines “organization” as an entity which “operates in or the activities of which affect interstate or foreign commerce,” the statute provides no such definition for the term “person.” Section 513 does not require the government to demonstrate an individual victim’s connection to interstate commerce. The uncontroverted evidence shows that the defendants sought to induce store employees to part with money in their possession through presentation of counterfeit documents. Ordinarily, where a defendant utilizes counterfeit securities in an effort to obtain property from or induce action by an organization, section 513 requires the government to prove the victim’s connection to interstate commerce. The instant scheme was structured to deceive the check-cashing employees; the charged offenses involved intent to deceive those persons. The government’s failure to demonstrate a connection of the grocery stores to interstate commerce, therefore, in the context of this case, does not render the evidence insufficient to support convictions under section 513.

Shephard further suggests that inasmuch as the government failed to prove the connection of MP & L to interstate commerce it did not prove that the offenses charged involved counterfeit securities of an “organization” as defined in section 513. The mere fact that the documents proffered to merchants in this scheme purported to be checks drawn on the account of MP & L in no way diminishes the fact that they also purported to be drawn on that company’s account at Trustmark. As the government points out, section 513 does not expressly or impliedly state that a document may be the security of only one organization. She-phard’s attempt to raise a sufficiency challenge by characterizing the counterfeit checks as “of MP & L” rather than as “of Trustmark” is frivolous. ^[10]

Finally, Chappell, Gibson, and Mitchem claim that the government failed to carry its burden of proof with regard to their involvement in the offenses charged, presenting proof only of their presence at the crime scene. We disagree. Review of the record indicates that the government presented evidence from which a reasonable jury could conclude that each actively participated in both the conspiracy and substantive offenses. This contention fails.

2. The Indictment

Shephard and Mitchem fault the district court’s denial of their motion to dismiss the indictment for failure to identify the victims of the cheek-passing scheme and their connection to interstate commerce. We review de novo district court rulings regarding the sufficiency of indictments. ^[11] An indictment need only charge the essential elements of the offense, permitting the accused to prepare a defense and protecting against double jeopardy. ^[12] Practical rather than technical considerations govern resolution of such challenges and we will not reverse for minor deficiencies which do not prejudice the accused. ^[13] The indictment in this case more than adequately alerted the defendants to the conduct prosecuted. It referred to section 513. ^[14] While a more careful drafting of[*1100] the indictment might have occurred, we perceive no prejudice to the defendants. ^[15]

3. Expert Testimony

Shephard next argues that the trial court improperly permitted Wayne Humphrey, Trustmark’s assistant security officer, to testify as an expert witness in the field of detecting counterfeit checks. Humphrey testified that irregularities in the checks, such as inaccurate routing and account numbers, incorrect electronic coding, and absence of perforation, identified them as forgeries. Shephard contends that “detecting counterfeit checks” does not constitute a proper field of expertise and that, in any event, Humphrey’s training as a bank security officer did not qualify him as an expert. Under Fed. R.Evid. 702, “[i]f ... specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill,, experience, training, or education may testify thereto in the form of an opinion or otherwise.” We will reject district court rulings on the admissibility of expert testimony only if manifestly erroneous. ^[16] Humphrey’s years of experience afforded specialized knowledge permitting him to assist the jury in evaluating the genuineness of the documents. The district court did not err in permitting his testimony.

4. Fourth Amendment

Mitchem assigns as error the district court’s ruling on his motion to suppress evidence recovered from his person and hotel room, claiming that they were fruits of an arrest without probable cause in violation of the fourth amendment. ^[17] Police may make a warrantless arrest where there is probable cause to believe that an offense has occurred. We previously have held that police officers may develop probable cause for a warrant-less arrest on the basis of information communicated to them by other officers. ^[18] We must accept trial court fact-findings made in the course of ruling on suppression motions unless clearly erroneous or influenced by an incorrect view of the law. ^[19] However, we review de novo its ultimate conclusion regarding probable cause. ^[20]

Here, the district court found that Davis observed Mitchem at the crash scene and transmitted a fairly detailed description of his physical appearance and clothing. Veaz- ey participated in a search for Mitchem at the crash site.- Two hours later and a. short distance away, Veazey observed. a muddy,[*1101] sweaty man matching the transmitted description wearing torn clothes attempting to flag down a car, who responded evasively when offered assistance.- The record supports the district court’s conclusion that Veazey arrested Mitchem with probable cause. ^[21]

5. Sentencing

a. Amount of Loss ,

Both Shephard and Mitchem challenge the district court’s finding as to intended loss under U.S.S.G. § 2F1.1. ^[22] The district court made this determination by adding together the values of the three checks charged in the indictment, a check cashed by the defendants in Frankfort, Kentucky, the five checks found by police in the getaway car, and 16 cheeks reflected on the typewriter ribbon, for a total of $4,296.29. It then assessed the value of the 51 blank cheeks found in the ear and hotel room at $13,617 by assigning to each the average value of the checks actually recovered. The district court thus concluded that the defendants intended to inflict a total loss of $20,838.75, resulting in a four-point offense level increase under U.S.S.G. § 2F1.1(b)(1)(E). Mitchem and Shephard argue that the district court should not have considered the 51 blank cheeks and, in any event, that it valued those documents in an arbitrary manner. These contentions misperceive the law.

We review district court determinations regarding amount of loss under U.S.S.G. § 2F1.1 under the clearly erroneous standard. ^[23] Commentary to section 2F1.1 states that “[f]or the purposes of subsection (b)(1), the loss need not be determined "with precision. The court need only make a reasonable estimate of the loss, given the available information.” ^[24] Further, the commentary indicates that “if an.intended loss that the defendant was attempting to inflict can be determined, this figure will be used if it is greater than the actual loss.” ^[25] The record in the instant case reflects that the defendants produced or attempted to negotiate at least 25 counterfeit checks having a total value of $4,296.29. In addition^ the defendants had in their possession the “Target 92” booklet, detailing a plan to pass as many as 155 checks in an effort to procure as much as $300,000. On the facts of this case, we cannot say that the district court acted improperly by including the 51 blank checks found in the car and hotel room, or by assigning to them the average value of the other cheeks actually produced and negotiated. ^[26] We conclude that the district-court’s assessment of intended loss was conservative; it manifestly was not clearly erroneous.

b. Upward Departure

Mitchem finally challenges the justification for and extent of the upward departure imposed by the district court. ^[27] Trial courts may impose sentences outside the range established by the guidelines in cases presenting “aggravating or mitigating[*1102] circumstance[s] of a kind, or to a degree, not adequately taken into account by the Sentencing Commission in formulating the guidelines that should result in a sentence different from that described.” ^[28] When imposing such a sentence, however, the district court must articulate on the record acceptable reasons for departure, ^[29] and the departure must be reasonable. ^[30] We review district court decisions to depart only for abuse of discretion. ^[31]

The Sentencing Guidelines expressly authorize departure where “rehable information indicates that the criminal history category does not adequately reflect the seriousness of the defendant’s past criminal conduct or the likelihood that the defendant will commit other crimes.” ^[32] Mitchem’s criminal history score of 25 far exceeded the minimum score for Criminal History Category VI and did not take into account several stale counterfeiting and forgery offenses. ^[33] These facts fully support the district court’s conclusion that Criminal History Category VI inadequately reflected the seriousness of Mitchem’s criminal background and likelihood of recidivism. They further support the reasonableness of the departure imposed. ^[34]

The convictions and sentences are AFFIRMED.