questionable search?

My 17 year old son was charged with 2 counts of paraphernalia and 1 count of tobacco possession after the police searched our home in Mississippi for over 3 hours. I was not present, but my wife was. Several aspects of this incident do not seem legitimate. At the hearing my son plead not guilty. He has trial in 3 weeks. I have requested a copy of the evidence against him. I haven’t hired a lawyer and not sure if I will. Here’s a brief outline of what happened:

My son and 4 of his friends were at our house. Two officers knocked on the door and spoke to my wife. They stated that they stopped at our house because a car was parked against the flow of traffic and upon stopping smelled marijuana coming from the house. My wife had just came home from work and said that she didn't smell anything. They then said that they “know” that drugs are in the house and if my wife didn't allow them to enter the house, then she could be prosecuted for the drugs. She agreed to the search.

We live in an upscale neighborhood with wide streets. It is not uncommon to find cars parked on the wrong side of the street. I've done it on occasion and never have been ticketed or questioned. Also, it’s a very large house on a large lot. The street is at least 100 ft away from the closest part of the house. In fact, there are 2 houses across the street that are actually closer to where the officers claimed to have noted the smell than our house. They didn't go to those houses. Probable cause seems very sketchy to me.

The police called in an undercover to assist in the search. They searched the house and questioned the kids for several hours. No drugs were found, but they did find 2 pipes and a cigarette butt in one of two rooms that my son uses.

At the hearing at an adult court my son plead not guilty on all accounts at my urging. Instead of announcing a court date and dismissing us like all the previous pleas were handled, he began asking my son questions. He asked if he was in school, what he wanted to do for a living, and other similar questions. Then out of nowhere, he asked my son if the pipes were his. I thought my son would say no. I explained to my son earlier that regardless of the truth let’s make them prove you committed a crime. Out of fear, anxiety, ignorance, take your pick… my son essentially admitted to it by saying yes but he doesn't do that stuff anymore and they were from a long time ago. The judge then stopped the questioning, said that if he was found guilty he’d be subject to a urinalysis, and then set the court date.

I’m an engineer, not a lawyer. I have no legal training, but this seems very wrong to me. Is there anything here to help me get this thrown out? I’m not sure if I want to spend several thousand on a lawyer for such a minor offense, but I don’t want my son to have this on his record either. With that said, I would like for him to get some community service or in some way make it painful for him in the short-term, but I definitely don’t want the paraphernalia charge to stay. I would be alright with the tobacco charge. My intention was to call the prosecutor to negotiate a plea. Ideally, I’d like the paraphernalia charges to be dropped, plead guilty to tobacco, and be given community service and/or entered in to a brief “scare” type program. I would even agree to periodic drug testing although I’m not sure if this is possible if he’s not convicted of any drug related offense.

Any and all advice is appreciated