If you're at least 18 years old, have a clean criminal history and can afford the application fees, you can get a license to work as a private investigator in the state of Iowa. The Iowa Department of Public Safety, or DPS, issues P.I. licenses under rules set by the Legislature in the Iowa Code.
You can't apply for a license online, but you can download the application at the DPS website, dps.state.ia.us. You must submit the application by mail, along with two copies of your fingerprints and two 1-by-1 inch color photos of your face. The photos must be less than a year old. You must pay the $100 license fee with your application, plus a $30 processing fee for checking your fingerprints and $10 for each state-issued private investigator ID card you want. If the department rejects your application, you'll get the license fee back, but not the fingerprint-processing fee. The license is good for two years; renewal costs $100.
To obtain a private investigator license in Iowa, you must be at least 18 and you cannot already be employed as a peace officer. You can't have any convictions for felonies or aggravated misdemeanors, misdemeanor weapons convictions, or misdemeanor convictions for crimes of "moral turpitude," including fraud, sexual misconduct, domestic violence, stalking, harassment and drug offenses. You can't have a "history of repeated acts of violence," according to the Iowa Code, and you can't be addicted to alcohol or drugs.
A private investigator in Iowa has to file a $5,000 surety bond with the DPS. The surety bond, which you must obtain from an insurance company licensed to operate in Iowa, exists to compensate people who suffer damages from your conduct. DPS also requires that you buy liability insurance in addition to the bond. The law doesn't say how much coverage you need; it's up to the discretion of officials at DPS.
On the Job
If you have a principal place of business, you must display your license in a conspicuous location there. You must carry your state-issued ID card whenever you are engaged in private investigation work. While working as a P.I., you can't conduct yourself in any manner that implies you are a law enforcement officer. That means you can't display any kind of badge unless DPS has approved it, and while you're allowed to give yourself some kind of "uniform" if you want, that uniform also has to be approved by DPS. Finally, you can get a permit to carry a gun by following the same procedures that apply to other citizens; contact your county sheriff's office for an application.