There could be other possible stores where the tainted product was returned, police said, but have not released those locations yet.
Tucson police are warning residents about possible tampering with infant formula and say one child has been released from a hospital after getting sick from ingesting tampered formula.
Laplante may be facing further charges; detectives are still looking into any returns she may have made.
The TPD said she bought the formula, replaced it with flour, sugar and rice cereal, resealed the cans and returned them to the store for a refund. LaPlante is accused of substituting flour for infant formula in containers returned to several local stores for refunds, and police have warned the public to check formula containers' seals for tampering.
Police listed two Fry's grocery stores and two Wal-Mart stores, all on Tucson's eastside, that are linked to the incident.
"Like everyone else, we are deeply disturbed by this situation and take it very seriously", a Walmart spokesperson told Tucson News Now "Our customers deserve safe, quality foods, and we have policies in place to help ensure that returned baby formula is not put back on our shelves".
"We checked all the other brands of baby formula to make sure there wasn't any other tampering just as a precaution", the spokesperson said.More news: Ujiri: Raptors need a 'culture reset' after being swept out of playoffs
She allegedly did this with Gerber "Good Start" Soy formula.
According to police, there may be other formulas that are tainted, but those brands are not known at this time.
Fry's personnel continued to assist in attempting to locate any returns of formula that may have been conducted at their stores.
Anyone with questions about the formula tampering can call Tucson police communications at 791-5059.
Suspicious formula can be taken to the department's evidence facility at 945 E. Ohio St., between 8 a.m. and 5 p.m. Friday through Sunday. She may not have worked alone, police said.
Magnus says the alleged scheme apparently was motivated by money and may have been going on for as long as two months.
Dr. Frank Lovecchio is the co-director of the Poison and Drug Information Center at Banner Health and shared some tips to follow when purchasing baby formula.